<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script src="./lib/react.js"></script>
    <script src="./lib/react-dom.js"></script>
    <script src="./lib/browser.js"></script>
</head>
<body>
    <div id="root"></div>
    <script type="text/babel">
        class APP extends React.Component{
            constructor(props){
                super(props)
                this.state={
                    num:0
                }
            }
            add(){
                this.setState({
                    num:this.state.num+1
                })
            }
            render(){
                return (
                    <div>
                        <button onClick={this.add.bind(this)}> + </button>
                        <h1>{this.state.num}</h1>
                    </div>
                )        
            }
        }
        
        ReactDOM.render(<APP/>,document.getElementById("root"))

    </script>
</body>
</html>